1. Field of the Invention
The present invention relates to a non-halogenated flame-retarded covered wire which is used in a field such as motor vehicle wherein flame retardance is required especially.
2. Description of the Related Art
A thin layer covered wire for motor vehicle use is arranged in a narrow space inside a motor vehicle and is always in an environment of vibration, oil and the like. That is, the thin layer covered wire for motor vehicle use is required to bear the severe condition, which is not required for a general covered wire, and further flame retardance, lightweight, and recently halogen-free as an environmental problem measures are required.
A polyolefin covered wire having a covered layer including a large quantity of magnesium hydroxide as a non-halogen flame retardant has come into use for satisfying such a requirement.
The addition of a large quantity of magnesium hydroxide, however, lowers other properties such as abrasion resistance and oil resistance which are required for a covered wire for motor vehicle use. Therefore, it is difficult to reduce a thickness of an insulating cover layer to 200 .mu.m which is applied to a polyvinyl chloride covered wire, and, at present, it is even difficult to make the thickness less than 300 .mu.m, thereby leaving problems of arrangeability, weight and thickness.